The present inventive concept relates to semiconductor devices and, more particularly, to semiconductor devices that include a capacitor.
As semiconductor devices are developed with high integration, capacitors may need to have a high capacitance in a limited area. The capacitance of the capacitor is proportional to a surface area of an electrode and a dielectric constant of a dielectric layer while being inversely proportional to an equivalent oxide thickness of the dielectric layer. Accordingly, to increase the capacitance of the capacitor within a limited area, a three-dimensional capacitor may be provided so that a surface area of the electrode is increased. Also, the capacitance of the capacitor may be increased by reducing the equivalent oxide thickness of the dielectric layer or by using a dielectric layer having a high dielectric constant.
The surface area of an electrode may be increased by increasing height of a lower electrode or a storage electrode, increasing an effective surface area of the lower electrode using a hemi-spherical grain (HSG), or increasing inner and outer surface areas of a cylinder by using a one cylinder storage (OCS) electrode.